Istanbul — Even amid the tragically high levels of war trauma in Yemen, the triple missile strike on a packed funeral hall by a Saudi-led coalition over the weekend stands out as a potential turning point for the outrage it has caused.

Inside Yemen, the shock of the strike in Sanaa, which killed some 140 mourners at the well publicized gathering – among them prominent figures who could have been instrumental in securing peace – has galvanized a desire for revenge, analysts say, that is likely to snuff out near-term peacemaking efforts while it further escalates fighting.

Elsewhere, the attack has raised renewed allegations of war crimes; prompted fierce denunciation by the UN chief; and incurred rare public criticism from Saudi Arabia’s close ally, the United States, which began an immediate review of military assistance provided since Riyadh began its air campaign in March 2015.

In a war now defined by civilian casualties at the hands of the Saudi-led coalition rather than any military achievement, the scale of the fallout is raising the question of whether Saudi Arabia can be pressured to change its war plan to roll back Yemen’s Shiite Houthi rebels and restore a Saudi-backed government.

“This is such a dramatic escalation,” says Adam Baron, a Yemen specialist with the European Council on Foreign Relations (ECFR), contacted in Beirut. “Even within war – and particularly in the Yemeni context – there are traditionally red lines. This was a flagrant crossing of a red line.”

Yemenis had been expecting an announcement of a cease-fire renewal, he says, not a Saudi strike that would be taken as a casus belli to expand a war that the UN estimates has already claimed 10,000 lives, more than 4,000 of them civilians.

Former president Ali Abdullah Saleh, a vital ally of the Houthis, who are loosely backed by Iran, called Sunday for “battle readiness at the fronts on the [Saudi] border.”

Saudi Arabia said it intercepted one Houthi missile fired more deeply inside its territory than ever before, toward Taif, in the center of the country near Mecca. A Houthi missile was also fired at a base of pro-Saudi forces in central Yemen.

On Sunday, two missiles were fired from Houthi-controlled territory at the USS Mason, a US Navy guided missile destroyer on patrol north of the Bab al-Mandab strait.

“There is potential for much greater infiltration of Saudi Arabia [and] a far greater chance of escalation on the Saudi border,” says Mr. Baron.

It remains to be seen, however, how far the Obama administration – which just last month approved a $1.15 billion arms sale to Saudi Arabia over protests from Congress – will go toward censuring the kingdom.

How would Saudis respond to pressure?

“The US is, in a lot of cases, literally refueling the planes that are being used in the bombing campaign,” says Mr. Baron. “Even though they have this leverage, you have yet to see any clear sign that the US is willing to use that leverage to pressure the Saudis.

“And there is the question of how the Saudis would respond,” he adds. “The Saudis view this as a crucial question of national security, and they view the Americans as just not understanding this threat.”

In a statement after the strike on the funeral, the White House condemned what it called the latest in a “troubling series of attacks striking civilians” in Yemen. It also launched an “immediate review of our already significantly reduced support” to the Saudi-led coalition, and said it was prepared to “adjust” its backing to “better align with US principles, values, and interests.”

“US security cooperation with Saudi Arabia is not a blank check,” said National Security Council spokesman Ned Price.

UN Secretary-General Ban Ki-moon was also withering in his denunciation of what he called “mounting crimes.”

“Aerial attacks by the Saudi-led coalition have already caused immense carnage and destroyed much of the country’s medical facilities and vital civilian infrastructure,” said Mr. Ban. “Excuses ring hollow given the pattern of violence.… A man-made catastrophe is unfolding before our eyes.”

That is not news to Yemenis in the Houthi-held part of the country, who have endured months of bombing of schools, hospitals, and factories with no endgame yet articulated by Saudi Arabia.

Neutral ground at funerals

But the funeral was not where anyone expected an attack.

“Cultural norms and tribal traditions are deeply respected in Yemen,” says Hisham al-Omeisy, a political analyst in Sanaa who knew several of the strike’s victims. Funerals are considered “neutral ground where even the most loathed enemies or rivals meet and are not to be touched, where custom dictates they’re to be treated with utmost respect.”

This funeral – of a well-known public figure from one of Yemen’s biggest tribes – attracted high-ranking officials, military and security chiefs, tribal leaders, and members of a wide range of political factions, including the mayor of Sanaa.

The airstrikes “not only killed folks who would’ve contributed to finding common ground,” says Mr. Omeisy. It also “pushed those who remained neutral to join a side and seek revenge for very grave insult and injury.”

Few in Sanaa believe the repeated strikes were not deliberate. Rather they were a “calculated risk” by the Saudis to remove leadership targets and weather the resulting blowback, suggests Omeisy. A number of pro-Houthi dignitaries – and perhaps even former president Saleh himself – had been expected to attend.

“We’re not that naïve to think the incident will prompt a major overnight shift toward Saudi, but very much welcomed strong and honestly unexpected statements,” says Omeisy, referring to those from the United States, Britain, and United Nations. “Who ever would have thought the US official text would read, ‘US cooperation is not a blank check?’ ”

Such sentiments have also grown in Washington. According to a Reuters investigation released Monday, one US official said that State Department lawyers “had their hair on fire” as reports of civilian deaths rose in 2015, and concern grew that the US could be implicated in war crimes as a “co-belligerent” by supporting the Saudi-led effort.

Countering the Iran deal

The US has sold more than $22.2 billion in weapons to Saudi Arabia since the campaign began more than a year ago, partly to offset Riyadh’s fears over the Iran nuclear deal that had just been agreed to. The Air Force Times reported in August that US refueling missions to the Saudi-led coalition had increased 61 percent compared with the previous February.

The US asked the Saudis to “exercise the utmost diligence in the targeting process” and provided “no-strike lists” for the Saudis, since hitting them could “do sufficient harm to Yemen’s ability to recover expeditiously” from the war, according to US talking points drafted in October 2015, Reuters reported.

At least one of those targets, a bridge that served as a primary aid supply route, was struck after a cease-fire collapsed last August.

A September report by the Yemen Data Project found that 1 in 3 of the 8,600 Saudi-led coalition air attacks targeted civilian sites – figures Riyadh says are greatly exaggerated. Added to that number will be the attack on the funeral.

While it may be more difficult to tell the difference between a wedding and a gathering of fighters in a rural setting, that is not true in one of the largest halls in the urban sprawl of Sanaa, says Baron of ECFR, who has attended weddings there and who lost friends in the attack.

“It is one of Yemen’s largest event halls, packed with people, and if you launch three missiles at it, there’s going to be a massive death toll,” says Baron. “It just boggles my mind that this could be cast as – quote, unquote – a ‘mistake.’ ”

“This is a country that more than anything needs this war to come to an end, yesterday,” he says.